Network not defaulting, Internet dropping out

Helllo forum. This is my first post. Recently our imac started to loose conection to our airport. The airport is working because the laptop hooks up straight away. Anyway you look something up on safari and it starts, then it just pauses. You have to go into system prefs, then network, to diagnostics, select location, select network (airport), then hit continue. It looks as though the automatic connection has stopped. Any ideas?

Members here sort of need some information on your hardware, OS, ... Pretty tough to troubleshoot when we don't know what you are working with...

In the netwok preferences there is a location menu at the top. Is your default connection under the location called automatic?